An apparatus consistent with the present invention relates to a magnetic tape cartridge, and more particularly to a magnetic tape cartridge which can prevent wear of the contact portion provided on the release pad to be rotated.
As a magnetic tape cartridge utilized for an external memory medium for backup of data of a computer and the like, there is a conventionally known magnetic tape cartridge that satisfies a so-called LTO (Linear Tape Open) standard. Such a magnetic tape cartridge rotatably accommodates a reel, onto which is wound a magnetic tape, in a cartridge case. In order to prevent an undesired rotation of the reel at a time when the magnetic tape cartridge is not in use, the rotation of the reel is locked by a reel lock that is usually urged toward the reel by means of a compression coil spring. The reel is unlocked during the use of the magnetic tape cartridge. The contact surface of the release pad urges a pivot provided at a center of the reel lock in an upward direction against the resilient force of the compression coil spring to disengage the lock state of the reel. During the use of the magnetic tape cartridge, the contact surface of the release pad and the pivot of the reel lock always contact each other while allowing the relative rotation thereof. The term “during the use of the magnetic tape cartridge” indicates a state where the reel drive mechanism of the drive device rotates the reel.
When the reel rotes, the urging force F is locally focused on the contacting point between the pivot of the reel lock and the contact surface of the release pad. Therefore, the contact surface suffers from partial wear by an extensive and long term use of the magnetic tape cartridge. Once partial wear occurs at the contact surface, the contact between the reel lock and the release pad becomes unstable which makes the reel lock tilt. This generates vibrations to be transmitted to the whole cartridge case, so that a strange noise occurs. This kind of problem becomes more and more serious with increasing demands for reading out the data or searching the program at high speed and also with increased speed of the rotation of the reel.
Therefore, in order to prevent wear of the contact surface, Japanese Laid-open Patent Application No.2002-197833 (paragraph 0016, and FIG. 5) discloses to attach a metal plate on the release pad to form the contact surface.
However, this conventional magnetic tape cartridge requires another assembling process to attach a metal plate on the contact surface of the release pad, leading to increased manufacturing cost.